I can remember Labour’s first party conference under Gordon Brown’s leadership being the most stupefyingly boring political event I’d ever covered. Not only were the official platform performances timed to the second and managed to within an inch of their lives, but even the fringe events were populated by blank-eyed Brownite zombies. It was, I jokingly reported, positively Stalinist in the obsessive control exercised by the leadership. Some joke.

Not being one of those journalists on intimate terms with Labour’s inner circle, I was unaware that the prime minister’s fanatically loyal team were stopping just short of murdering their enemies and expunging their images from the historical group photographs. The gothic-horror tale of the Blair-Brown years – complete with repentance and public rending of garments – will now play itself out in confessions of competing repulsiveness. Damian McBride’s self-flagellation will alternate with the Blairite army’s “we did what we had to do” (because, after all, we were up against a crazy person) admission of a kind of guilt. And all this during the week in which the hapless Ed Miliband was supposed to be restoring his party’s sense of honourable purpose.

Not wishing to detract in any way from the righteous delight of those who are not Labour supporters, I have to say that there is a warning in all of this for everybody in political life. The “devotion” and “love” that Mr McBride expresses for his leader – which were not unlike the testimonies of undying fealty offered to Tony Blair by Peter Mandelson and Alastair Campbell – sound creepy and rather weird in the horribly cold light of morning.

But are they so very different from what all parties are now expected to provide for their leaders? Maybe not love – in what appears to be the almost libidinous sense implied by Labour acolytes – but certainly obeisance and utterly disciplined fidelity.

Nick Clegg was judged last week to have had an amazingly (or surprisingly?) successful conference because he effectively suppressed any possible threat to his personal ascendancy. His judgments went without any effectual challenge, even from the previously dangerous Vince Cable. He managed to do what the Westminster elites always believe to be critical for a party leader: he “stamped his authority”, as the lobby correspondents say, on his party. All dissidence was eliminated. Any potential challenge to Mr Clegg’s judgments – however bizarre and voter-repelling they were – had “disappeared” in the great tradition of Latin American dictatorships. So Mr Clegg had a “good” conference.

This week, Mr Miliband might end up having as good a conference as could be expected under the circumstances if – what? He succeeds in a stupendous act of repression which effectively silences his critics. If there are no restive outbreaks of rebellion or discord on the fringe, and no treacherous briefings from shadow-cabinet colleagues to the effect that Mili Minor does not have enough to say about issues of national concern such as education and welfare, and no audible dissatisfaction among the rank and file – then Ed will be judged to have “proved himself” as a leader.

The week after that, it will be David Cameron’s turn to “stamp his authority” on his party. If he can suffocate any querulous objections before they reach the public ear, clamp shut the mouths of his most dogged backbench critics, and impose a monolithic message on the party rank-and-file, then he, too, will have a “successful” conference that will ensure his credibility, blah-blah. In other words, the test of whether political leaders are fit for purpose is how effective they are at shutting down argument.

Why? Are we all fascists now? When exactly did this Führerprinzip take hold in British public life?

I have always assumed that the right to express differing opinions and debate ideas was the great virtue of democratic politics, not just for the sake of abstract freedom but also because it is through the process of critical argument that we arrive at the best solutions.

It seems tragic to me that ordinary voters seem to have developed such an aversion to the very idea of disagreement between politicians. Like children who don’t want to hear Mummy and Daddy arguing, they say, “Why can’t they just get together and agree on what to do?” – apparently forgetting that any such comprehensive agreement between parties would leave them without a choice, and thus without a voice, in how they were governed. (Oddly, this desire to have decisions taken out of their hands coexists with a record amount of dissatisfaction with politicians themselves.)

In fact, Mr Clegg espoused precisely this childlike ideal of politics last week: in which the power elites of the nation trade off their various contradictory principles until, like “reasonable people”, they reach an accommodation they can all accept. Quite apart from the fact that this model leaves the voter nowhere in the picture, it rests on the assumption that there must be a solution to every political dilemma in the negotiable middle: that there are no values and principles that are flatly irreconcilable with one another, about which we must argue and debate until we put them to the vote of the people.

The Big Argument of the 20th century between socialism and capitalism is finished. So the public debate is now over fine distinctions about how much or how little government we need, about levels of taxation and public spending and how they affect individual lives. But because the disagreements are more subtle and detailed, it is all the more important that they be openly discussed and disputed. The balance between state power and free markets will never be definitively settled. The conflict between individual rights and social cohesion will need to be reassessed and revisited constantly. These debates will never – should never – end. Between and within parties, passionate disputation should be seen as a source of strength and vitality. A party that is mutely united must be either brain-dead or terrorised into submission.

Of course, if parties are existentially divided within themselves to the extent that they are paralysed, then they cannot govern. If Labour is unable to decide, for example, whether it is a sectarian interest group or a national political force, then it will have to argue itself hoarse until it reaches a conclusion.

But if its conference fringe is full of fury and angst, that will be a sign that it is engaging in just that process, rather than stamping it out and drowning anyone who stands in the way.

As Nigel Farage put it in his sweaty speech to Ukip’s fledgling party conference, people aren’t turned off by politics – they are turned off by the political class who won’t permit “open and honest debate”. That observation may turn out to be his most important contribution to public discourse.